Method of making ingot molds



192 March 8 7 G. A. DoRNlN METHOD 0F MAKING INGOT HOLDS original FildApril 1e, 1925 2 Sheets-Sheet l Barnim 1,620,0114 G. A. DORNIN METHOD oFMAKING INGOT uoLDs March 8 1927.

original Filed April 16. 1925 2 Sheng-sneek 2 @www Patented Mar. 8,.1927.

UNITED STATES PATENT oFFlcE.

GEoEGE A. noENIN, or BALTIMORE, IIAE'TEANII''Assrefafon ro THEGA'rn'MANN' o ENGINEERING COMPANY, or BALTIMORE, MARYLAND.

METHOD F MAKING INGOT HOLDS.

Original application illed April 16, 1925, Serial No. 23,586. Dividedand this application tiled Septemb 4, 1925. Serial No. 54,519. i

'This invention relates to metal molds of a kind commonly used forcasting steel ingots and particularly to molds of this class in whichthe lowerV part of the mold Walls are made thicker than the uppenpartthereof and in which the mold cavity is made ofv larger diameter at thetop of the mold than at the bottom thereof. This is a characteristic ofthe Gathmann molds now in general use.

In the casting of metal mblds of the kind just referred to. it has beenfound that better results are obtained when the sand molds in which themetal molds are cast, are bottom poured, withoutv a cope or cover, the

molten metal being caused to rise in the sand mold until the desiredsize-and shape is 0btained. This method of casting ingot molds is sogreatly superior to other methods that it has been generally adopted. Ithas, however, one defect. The upper surface of the casting when formedis quite rough and uneven and in such condition the mold is not suitablefor use inasmuch as the top surface of the casting which constitutes thebottom of the ingot mold when in use will not rest properly on a stoolor support. Therefore the common practice heretofore has been to removethis rough surface by suitable tools or machine driven implements. Thisoperation however, adds considerably to the cost of the mold and suchcost naturally goes into the cost of the ingot and consequently into thecost of the steel. f I have found a most simple. cheap and efficient wayof removingr these objections and I do this during the process ofcasting the mold so that the subsequent operation of machining the moldbottom is rendered unnecessary.

The preferred wayof lcarrying out my invention is illustrated in theaccompanying drawings in which- Figure 1 is a view partly in ,sideelevation and partly in vertical section of an ingot mold made by myimprovements and showing how it is supported. Figure 2 is atop plan-view thereof.

Figure-,3 shows a vertical section of the lower part of the mold showinghow it enters thestool or support. the section being taken on the lineB--B of Figure 2.

Figure 4 shows a vertical sectiony of the lower portion of the mold andthe stool.

Figure 5 shows a vertical section of a sand mold with my improvementsapplied and shows how the metal molds cast therein.

Figune 6 is a top plan view of a sand mold.

In Figure 1 a mold of the Gathmann type is indicated at A. B indicates astool and C a truck on which the 'stool is supported.

In eneral the mold A is of usual construction but it differs fromoth-ers in the formation of its bottom wall.

It will be observed that the central part a of the bottom extendsbelowlthe` marginal portions b thereof-and that while the under side ofthecentral portion is rough and uneven, the marginal portions are smoothand even so that the mold is held in a truly vertical position whenplaced on its stool. These smooth marginal portions are preferablyformed on two sides only of the mold, but they may extend continuouslyor at intervals entirely around the mold. These smooth marginal portionsare produced during the process of casting.

Figures 5 and 6 illustrate how the smooth and even marginal portions areformed in' the mold during the casting operation.

A sandl mold of well known construction is illustrated, at D,- the sandparts being shown at d and the flask or frame parts being shown at d.The ingot mold cast in the mold is shown at A. The mold is bottom pouredbeing supplied with molten metal by a feeding device E of well knownconstruction. spects to those .heretofore used but I provide means atthe top of the sand moldfor producing the smooth and even"marginal portions of the ingot mold before referred to. The simplest and best waynow known to me for performing this function is to support on the top ofthe sand mold two heavy metal The sand mold is similar in all rebars Fhaving smooth under sides. As the molten met-al rises in the san'd mold,it comes in contact with these bars and is chilled thereby. After themetal reaches the level of the chill bars. it continues to rise betweenthese bars until it rises a suiiicient distance above their bottom, orhigh enough to slightly overow the sand mold. at which time the kish orimpurities which accumulate in the metal during pouring can be scrapedor raked oi sidewise between the chill bars. This operation of rakingoff kish is a necessary part of forming ingot molds in open top sandmolds when said ngot molds are poured from direct metal. In this waysmooth, even marginal parts are formed on opposite sides of the middleportion of the bottomof the mold which extends between the bars asindicated in Figure 5. When the metal mold is completed, the sand moldis withdrawn and in use the metal mold is reversed and supported in themanner indicated in Figure 1. v

It will be observed that the sand mold is so constructed and its core isso formed that a metal ingot mold of the big-end-up type is producedwith an opening 1n its bottom to receive a plug P which is generallyemloyed in this class of molds to close the ottom of the mold and toprovide a strip-E ping devioe. i

This application is a division of my application for Patent, Serial No.23,586, filed Apr. 16, 1925, in which claims are made to the novelfeatures of the mold herein shown and described.

I claim as my invention:

The method hereinbefore described of casting an ing'ot mold, whichConsists in bottom pouring a sand mold to cast the ingot moldbottom-side up, forming smooth, hard ledges on the top of the castingwhen the molten metal has risen to the upper portion of the sand moldand allowing a middle or central portion of the molten metal to riseabove said smooth ledges to thus separate impurities from that part ofthe casting where then ledges are formed.

In testimony whereof, I have hereunto subscribed my name.`

' GEORGE A. DORNIN.

